Attaching member



Oct. 24, 1933. G. JOHNSON 1,931,728Y

ATTACHING MEMBER Original Filed Feb. 2l, 1930 Patented Oct. 24,' 1933 UNrre Sars FFME y to United-arr Fastener Corporation, Cambridge, Mass., a corporation of Massachusetts Original application February 21, lt, Serial ay 430,36. Divided and this application' vernber 7, 1939. Serial No. 494,031

(C1. SiS-m11) Z Claims.

My invention aims to provide improvements in attaching members and more particularly to improvements in sheet metal rivets or tacks for attaching buttons, snap fastener elements and the 5 like to their carrying mediums.

Attention isfdirected to my application Serial No. 430,386, filed February 21, 1930, of which this application is a division. Y

In the drawing which illustrates. a preferred 10v embodiment of my inventionz` Figures 1 through 7 show a plan and crosssection of a step in the process of forming my device from the hat disc to the complete sharp pointed tack;

Fig. 8 is an enlarged elevational view of the dem Vice shown in Fig. 6, and showing the aperture in the shank of the tack;

Fig. 9 is a view of the complete tack showing the aperture closed;

Fig. l is a view showing the die means for pointing the apertured end of the shank of the tack just prior to compressing the material;v

Fig. 1-1 is another View of the means shown in Fig. l0 after the dieshave been forced together and the end of the tack has been pointed; and

Fig. 12 includes a section of a socket member of a snap fastener and a section of a stud member of a snap fastener, each fastener member being secured to a carrying medium by my improved attaching members.

Referring to the embodiment of my inventionselected for illustration in the annexed drawing, I have shown a self-piercing rivet orl tack which is formed from a single piece of sheet metal. The tack may be made of brass, steel or the like in a suitable machine by passing a piece of metal beneath a series of pressing dies in a step by step manner as will be readily understood from an inspection of the figures of the drawing by anyone 40 skilled in the art.r l

The various forms shown by Figs. l through are so obviously illustrative of the steps of one method of forming my sheet metal tack that they need no description and, therefore, I shall continue from that point to describemy invention so that it wiil be readily understood by anyone skilled in the art.

In Fig. 6 I have shown a tack having a base l and a hollow shank 2. The shank has been cut away on a line extending at an angle to the axis of the shank to remove some of the metal adjacent to the end, thereby forming an aperture 3. Any suitable method may be used to cut away a portion of the end of the shank, butI have provided an attachment on the machine which opked as a means of attaching snap fastener memerted upon the fastener installations.

erates transversely to the axis of one of the dies and cuts awaya portion of the end of the shank after the blank has assumed the shape shown in Fig. 5.

After the blank has been formed and out as shown in Fig. 6, it is forced into a female forming die A by a male die B, as shown in Fig. 10, where the end of the shank is pressed into a symmetrical sharp pointed portion fi, as shown in Figs. 9 and l1. Thus the opening in the shank adjacent to the end is closed (Fig. 9) to provide a smooth substantialiy continuous outer surface and the tack is ready for use.

My improved rivet kor tack is particularly adaptbers to their carrying mediums, as shown in Fig. 12. In that figure I have shown a socket 5 attached by a tack which has pierced the carrying medium 6 and has its end upset against a reinforced portion 7 of the socket which surrounds the aperture 8 through which the shank 2 passes. A stud 9 is also shown, in Fig. 12, secured to itsY carrying medium l0 in substantially the same manner as the socket 5.

I am aware of the fact that fastener members have been attached by tacks and by tubular rivets but, so far as I have been able to ascertain, no one has been successful in making a tack of sheet metal and with a sharp point so that it can pierce its own way through cloth, leather, cardboard or the like. I-Ieretofore, the tacks which have been used for attaching buttons, snap fasteners and the like were of the type commonly called cut tacks having solid shanks. Those tacks are not adapted to be used as rivets because in many instances the ends are broken when they are upset and if the riveting operation is successful the metal is so weakened that the upset portions will break loose under ordinary strains eX- Vexerted without in any way breaking or loosening the shank of the tack from its grip on the fas- 'ener member.

lWhile there are several ways in which I may accomplish the pointing of my sheet metal tack I have found that the method described above and illustrated in the drawing accomplishes the desired result in a Very efiicient and simple manner. It is particularly adapted for quantity production methods. Therefore, while I have illustrated and described a preferred embodiment of my invention `I do not wish to be limited thereby, because the scope of my invention is best dened in the following claims.

I claim:

1. A self-piercing tack formed from a single piece of sheet metal and having a base, a hollow shank formed from the center of said base and a conical, sharp pointed end on saidfshank having a closed perforation therein extending from a point adjacent to the end of the point toward the base for the purposes described and said pointed end on said shank being otherwise smooth throughout the exposed surface thereof.

2. A self-piercing sheet metal tack for attaching snap fastener members, buttons and the like, comprising a head7 a hollow shank integral with and extending from said head, a conical, sharp pointed end' on said shank having a single closed perforation, said perforation extending substantially the length of the conical portion at one side only whereby said pointed portion may be weakened to permit relatively easy deformation 

